diff --git a/gtk2_ardour/export_report.h b/gtk2_ardour/export_report.h
index 23a4870658..8a8326ee30 100644
--- a/gtk2_ardour/export_report.h
+++ b/gtk2_ardour/export_report.h
@@ -16,6 +16,9 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#ifndef _gtkardour_export_report_h_
+#define _gtkardour_export_report_h_
+
 #include <cairo/cairo.h>
 #include <gtkmm/notebook.h>
 #include <gtkmm/togglebutton.h>
@@ -227,3 +230,5 @@ private:
 	int _audition_num;
 	int _page_num;
 };
+
+#endif
diff --git a/gtk2_ardour/loudness_dialog.h b/gtk2_ardour/loudness_dialog.h
index 83b3970565..3a3c98abda 100644
--- a/gtk2_ardour/loudness_dialog.h
+++ b/gtk2_ardour/loudness_dialog.h
@@ -16,6 +16,9 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#ifndef _gtkardour_loudness_dialog_h_
+#define _gtkardour_loudness_dialog_h_
+
 #include <gtkmm/box.h>
 #include <gtkmm/expander.h>
 #include <gtkmm/label.h>
@@ -144,3 +147,5 @@ private:
 	bool  _ignore_preset;
 	bool  _ignore_change;
 };
+
+#endif